HUANG Kuangshi;LIU Hongyan
China Population and Development Research Center;China Population and Development Research Center
Based on the de jure population database of the 121 national monitoring counties in 2013 from the National Health and Family Planning Commission, this study employs the revised Lee-Carter model to decompose the second birth intervals for women aged 20 to 50 between 1980 and 2013 into three parts: the age-specific minimum second birth interval, the age-specific elasticity of the second birth interval, and the overtime change of the second birth interval. The results show that the minimum second birth interval ranges from 1.2 to 1.7 years. Increasing age of women is associated with increasing minimum second birth interval. The age-specific elasticity curve demonstrates an S-shape, which fluctuates gently between age 20–30, increases linearly between age 30–45, and declines slightly after age 45. Finally, the time effect on the second birth interval is negative between 1986 and 1996 while it is positive between 1980 and 1985 and between 1997 and 2013. These findings may help deepen our understanding of the age-specific pattern and time fluctuation of the second birth interval in China.
birth interval;Lee-Carter model;second birth interval